Healthy males (n = 16, age 22 ± 1 years), recruited from the University of Oxford, were randomised to five days of a high fat diet (HFD) containing 75 ± 1% of calorie intake through fat consumption, or an isocaloric control diet, providing 23 ± 1% of calorie intake as fat. In a cross-over design, subjects undertook the alternate diet after a two week wash out period. Cardiac 31P magnetic resonance (MR) spectroscopy was performed to assess PCr/ATP before and after the diets. MR imaging and echocardiography were performed to assess left ventricular function.

We have shown a short term, high fat diet raised plasma FFA concentrations, impaired myocardial energetics without effect on systolic or diastolic function. This suggests that high plasma FFAs may be detrimental for heart in normal subjects and shows a potential mechanism of impairment in heart failure patients.